When it comes to database management, there are many tools and features that can enhance the performance and efficiency of data retrieval. Among these, views play a crucial role in organizing and presenting data in a user-friendly manner. In particular, Oracle offers two types of views - Oracle views and materialized views. While both serve a similar purpose, there are distinct differences between them. In this article, we will explore the distinction between Oracle views and materialized views and understand their functionalities.
Firstly, let us understand what views are. Views are virtual tables that do not store any data but provide a virtual representation of data from one or more tables. Views are created based on queries, making them dynamic and flexible. They can be used to retrieve data from multiple tables, perform calculations, and present data in a customized format. This makes views a powerful tool for data manipulation and analysis.
Oracle views, also known as regular views, are the most commonly used type of views in Oracle databases. They are created using the CREATE VIEW statement and can be queried like any other table in the database. The data in an Oracle view is not physically stored, but it is retrieved from the underlying tables every time the view is accessed. This means that any changes made to the underlying data will be reflected in the view, making it a real-time representation of the data.
On the other hand, materialized views are a specialized type of views that store the result set of a query physically. This means that the data in a materialized view is stored in a separate location from the underlying tables. Materialized views are created using the CREATE MATERIALIZED VIEW statement and can be refreshed periodically to keep the data up to date. This feature makes materialized views an excellent option for improving the performance of data retrieval, especially for large and complex queries.
One significant difference between Oracle views and materialized views is their storage and performance. Oracle views do not require additional storage space as they do not physically store data. However, this means that the data is retrieved every time the view is accessed, which can result in slower performance for complex queries. On the other hand, materialized views have their own storage space, which can improve the performance of data retrieval, especially for frequently accessed data.
Another difference between the two types of views is their refresh capabilities. Oracle views do not need to be refreshed as they retrieve data from the underlying tables every time they are accessed. In contrast, materialized views can be refreshed manually or automatically based on a predefined schedule. This feature allows materialized views to provide up-to-date data without the need to query the underlying tables every time.
In summary, Oracle views and materialized views are both valuable tools in database management, but they serve different purposes. Oracle views are ideal for real-time data representation and manipulation, while materialized views are best suited for improving the performance of data retrieval. Understanding the distinction between the two types of views is crucial in deciding which one to use for a particular task. We hope this article has provided you with a better understanding of Oracle views and materialized views and their functionalities.
